it sounds as though the lock may be binding up internally, or there may be something wrong with the main spring, or the flint set, or perhaps the frizzen spring.
I suspect that you're in a sort of catch 22, writ large: you can replace the lock outright, at great expense, or you can tinker with it (and probably mess up some parts and replace them and thus get smart on your own) at great expense, or you can take it to a gunsmith who knows their way around flintlocks at great expense. yes, a pattern is developing here: the "great expense" thing ...
I would tinker with it, break some parts, eventually figure it out, and spend more than the whole thing is worth, but then again, I never did have much use for cost efficiency, and I love to take stuff apart -- that's just me ...
if you could post some photos ... also, does the lock function properly when it's been removed from the rifle? this would be symptomatic of other problems ...
:hmm: :hmm: :hmm: